Sentinel node biopsy for oral and laryngopharyngeal squamous cell carcinoma: a retrospective study of 177 patients in Japan

Sentinel Node Biopsy in Laryngeal Cancer: A Systematic Review and Meta-Analysis

Background: Sentinel lymph node (SLN) biopsy offers a minimally invasive approach to staging lymph node involvement in laryngeal squamous cell carcinoma (SCC). Despite its adoption in other cancers, its accuracy in laryngeal SCC remains under investigation. This systematic review and meta-analysis evaluates the diagnostic performance of SLN mapping in laryngeal cancer. Methods: A systematic search of MEDLINE, Scopus, and Google Scholar was conducted using the keywords "(larynx OR laryngeal) AND sentinel", with no date or language restrictions. Studies reporting SLN detection rates and/or sensitivity in laryngeal SCC were included. A random-effects model was applied for data pooling, and subgroup analyses were performed based on tumor location (supraglottic versus transglottic) and mapping material (radiotracer versus blue dye). Publication bias was assessed using funnel plots and statistical methods. Results: Nineteen studies, encompassing 366 patients, were analyzed. The overall pooled SLN detection rate was 90.8% (95% CI: 86-94.1), and sensitivity was 88% (95% CI: 81-94). Supraglottic tumors demonstrated superior outcomes (detection rate: 93.7%, sensitivity: 96%) compared to transglottic tumors (detection rate: 84.7%, sensitivity: 71%). Radiotracers significantly outperformed blue dye, with detection rates of 90.8% versus 81.5% and sensitivities of 88% versus 77%. Conclusions: SLN mapping is a reliable technique for staging laryngeal SCC, particularly for supraglottic tumors, where high detection rates and sensitivity were observed. Radiotracers offer superior performance compared to blue dye, underscoring their clinical value. These findings support the feasibility and accuracy of SLN biopsy in laryngeal cancer, while emphasizing the importance of tumor location and mapping material.

Intra-operative lymphatic mapping and sentinel node biopsy in laryngeal carcinoma using radiotracer injection

OBJECTIVE

The purpose of this study was to determine the value of sentinel lymph node biopsy (SLNB) in the laryngeal SCC, using intra-operative peri-tumoral injection of Tc-99m-phytate.

METHODS

Patients with biopsy-proven squamous cell carcinoma of the larynx were included. On the day of surgery, after anesthesia induction, suspension laryngoscopy was performed to inject 74 MBq/0.4 ml Tc-99m-phytate in four aliquots into the sub-mucosal peri-tumoral location. After a 10-min wait, a portable gamma probe was used to locate sentinel nodes. Subsequently, all patients underwent laryngectomy and neck dissection. Both sentinel nodes and non-sentinel nodes were examined using hematoxylin and eosin (H&E) staining.

RESULTS

Twenty-six patients with a diagnosis of laryngeal carcinoma were included in the study. The SLN detection rate was 65.4%, with a 100% detection rate in the supraglottic region and a 52.6% detection rate for glottis/transglottic patients. Permanent pathology results showed lymph node involvement in four patients, but only one patient had a negative result in the SLNB, resulting in an overall false negative rate of 25%. The sensitivity of the SLN technique was 75% overall, 100% in the supraglottic region, and 67% in the glottis/transglottic region.

CONCLUSION

The accuracy and feasibility of SLNB may be related to the location of the tumors in the larynx. For supraglottic tumors, the technique seems to be feasible with a low false negative rate. For glottis/transglottic tumors, both the detection rate and false negative rate seem to be suboptimal. Further studies are needed to validate our results.

Predictive factors for dissection-free sentinel node micrometastases in early oral squamous cell carcinoma

This sentinel node (SN) biopsy trial aimed to assess its effectiveness in identifying predictive factors of micrometastases and to determine whether elective neck dissection is necessary in oral squamous cell carcinoma. This retrospective study included 55 patients from three previous trials, with positive SNs. The relationship between the sizes of the metastatic focus and metastasis in non-sentinel node (NSN) was investigated. Four of the 55 largest metastatic focus were isolated tumor cells, and the remaining 51 were ranged from 0.2 to 15 mm, with a median of 2.6 mm. The difference of prevalence between 46 negative- and 9 positive-NSN was statistically significant with regard to age, long diameter of primary site and number of cases with regional recurrence. In comparing the size of largest metastatic focus dividing the number of positive SN, with metastaic focus range of < 3.0 mm in one-positive SN group, there were 18 (33%) negative-NSN and no positive-NSN. Regarding prognosis, 3-year overall survival rate of this group (n = 18) and other (n = 37) were 94% and 73% (p = 0.04), and 3-year recurrence free survival rate of this group and other were 94% and 51% (p = 0.03), respectively. Absolutely a further prospective clinical trial would be needed, micrometastases may be defined as solitary SN metastasis with < 3.0 mm of metastatic focus, and approximately 33% of neck dissections could be avoided using these criteria.

Predictive factors for false negatives following sentinel lymph node biopsy in early oral cavity cancer

Prophylactic elective neck dissection (ND) with navigation surgery using radioisotope-based sentinel lymph node biopsy (SLNB) is non-inferior to elective ND in terms of survival but has an advantage in postoperative functional disability. We conducted a subgroup analysis to identify predictive factors for false-negative (FN)-SLNB in patients with early oral cavity cancer. This study is a supplementary analysis using the dataset of a previously reported randomized clinical trial on SLN navigation surgery for oral cancers. This study investigated the association of clinical and SLN-related factors with false-negative cases in the SLNB group. From 2011 to 2016, 275 patients were enrolled and randomly assigned to the ND and SLNB study groups, with 134 patients assigned to the SLNB group. In the SLNB group, seven cases with negative SLNs and neck recurrences were judged as FN-SLNBs according to the general definition. The number of detected SLNs with and without adjusting for the propensity score was significantly associated with FNs in the logistic analysis. FN-SLNB was associated with the number of identified SLNs, suggesting the need for careful postoperative monitoring for neck recurrence in patients with one or two identified SLNs after acquiring sufficient experience in the identification technique.

A Systematic Review of Oral Biopsies, Sample Types, and Detection Techniques Applied in Relation to Oral Cancer Detection

Background: Early identification of the stage of oral cancer development can lead to better treatment outcomes and avoid malignant transformation. Therefore, this review aims to provide a comprehensive overview that describes the development of standardized procedures for oral sample collection, characterization, and molecular risk assessment. This can help investigators to choose the appropriate sampling method and downstream analyses for different purposes. Methods: This systematic review was conducted according to the PRISMA guidelines. Using both PubMed and Web of Science databases, four independent authors conducted a literature search between 15 and 21 June 2021. We used key search terms to broaden the search for studies. Non-conforming articles were removed using an EndNote-based and manual approach. Reviewers used a designed form to extract data. Results: This review included a total of 3574 records, after eliminating duplicate articles and excluding papers that did not meet the inclusion criteria. Finally, 202 articles were included in this review. We summarized the sampling methods, biopsy samples, and downstream analysis. The biopsy techniques were classified into tissue and liquid biopsy. The common sequential analysis of tissue biopsy includes histopathological examination such as H&E or IHC to identify various pathogenic features. Meanwhile, liquid samples such as saliva, blood, and urine are analyzed for the purpose of screening to detect mutations in cancer. Commonly used technologies are PCR, RT-PCR, high-throughput sequencing, and metabolomic analysis. Conclusions: Currently, tissue biopsies provide increased diagnostic value compared to liquid biopsy. However, the minimal invasiveness and convenience of liquid biopsy make it a suitable method for mass screening and eventual clinical adoption. The analysis of samples includes histological and molecular analysis. Metabolite analysis is rising but remains scarce.

Neck Dissections Based on Sentinel Lymph Node Navigation Versus Elective Neck Dissections in Early Oral Cancers: A Randomized, Multicenter, and Noninferiority Trial

PURPOSE

This study aimed to compare patients with early oral cavity squamous cell carcinoma (OCSCC) (tumor category [T] 1-2, node-negative, and no distant metastasis) treated with traditional elective neck dissection (ND) with those managed by sentinel lymph node biopsy (SLNB) using survival and neck function and complications as end points.

METHODS

Sixteen institutions in Japan participated in the study (trial registration number: UMIN000006510). Patients of age ≥ 18 years with histologically confirmed, previously untreated OCSCC (Union for International Cancer Control TNM Classification of Malignant Tumors 7th edition T1-2, node-negative no distant metastasis), with ≥ 4 mm (T1) depth of invasion, were randomly assigned to undergo standard selective ND (ND group; n = 137) or SLNB-navigated ND (SLNB group; n = 134). The primary end point was the 3-year overall survival rate, with a 12% noninferiority margin; secondary end points included postoperative neck functionality and complications and 3-year disease-free survival. Sentinel lymph nodes underwent intraoperative multislice frozen section analyses for the diagnosis. Patients with positive sentinel lymph nodes underwent either one-stage or second-look ND.

RESULTS

Pathologic metastasis-positive nodes were observed in 24.8% (34 of 137) and 33.6% (46 of 134) of patients in the ND and SLNB groups, respectively (P = .190). The 3-year overall survival in the SLNB group (87.9%; lower limit of one-sided 95% CI, 82.4) was noninferior to that in the ND group (86.6%; lower limit 95% CI, 80.9; P for noninferiority < .001). The 3-year disease-free survival rate was 78.7% (lower limit 95% CI, 72.1) and 81.3% (75.0) in the SLNB and ND groups, respectively (P for noninferiority < .001). The scores of neck functionality in the SLNB group were significantly better than those in the ND group.

CONCLUSION

SLNB-navigated ND may replace elective ND without a survival disadvantage and reduce postoperative neck disability in patients with early-stage OCSCC.

Unilateral versus bilateral nodal irradiation: Current evidence in the treatment of squamous cell carcinoma of the head and neck

Cancers of the head and neck region often present with nodal involvement. There is a long-standing convention within the community of head and neck radiation oncology to irradiate both sides of the neck electively in almost all cases to include both macroscopic and microscopic disease extension (so called elective nodal volume). International guidelines for the selection and delineation of the elective lymph nodes were published in the early 2000s and were updated recently. However, diagnostic imaging techniques have improved the accuracy and reliability of nodal staging and as a result, small metastases that used to remain undetected and were thus in the past included in the elective nodal volume, will now be included in high-dose volumes. Furthermore, the elective nodal areas are situated close to the parotid glands, the submandibular glands and the swallowing muscles. Therefore, irradiation of a smaller, more selected volume of the elective nodes could reduce treatment-related toxicity. Several researchers consider the current bilateral elective neck irradiation strategies an overtreatment and show growing interest in a unilateral nodal irradiation in selected patients. The aim of this article is to give an overview of the current evidence about the indications and benefits of unilateral nodal irradiation and the use of SPECT/CT-guided nodal irradiation in squamous cell carcinomas of the head and neck.

Attempting to define sentinel node micrometastasis in oral squamous cell carcinoma

OBJECTIVE

The aim of this supplemental study of a sentinel node (SN) biopsy (SNB) trial for oral squamous cell carcinoma (OSCC) was to assess the effectiveness in identifying micrometastasis and determining whether elective neck dissection (END) is necessary.

MATERIALS AND METHODS

Twenty-three patients with pathologically positive SNs were included. The sizes of the metastatic lesions in positive SNs (SMSNs) were classified and the rates of occult metastasis of non-SNs were compared.

RESULTS

The patients were divided according to the SMSN:<0.2 mm (group A, n=3);0.2 mm to <2.0 mm (group B, n=7);and ≥2.0 mm (group C, n=13). The rates of occult metastasis in groups A, B, and C were 0% (0/3), 14% (1/7) and 23% (3/13), respectively.

CONCLUSION

Rare cancer cell distribution to nodes other than SNs was observed in the patients with SN metastatic lesions of at least smaller than 0.2 mm in size, suggesting the possibility of defining SN micrometastasis in N0 OSCC.

Usefulness of Sentinel Lymph Node Biopsy for Oral Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

We assessed the diagnostic accuracy of sentinel lymph node biopsy (SLNB) for detecting neck nodal metastasis in early oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection.

STUDY DESIGN

A systematic search for relevant literature was conducted in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane databases.

METHODS

Two reviewers individually searched the five databases up to November 2019. For studies that met inclusion criteria, data on patient diagnoses were pooled, including true positives, true negatives, false positives, and false negatives. Methodological quality was checked with the Quality Assessment of Diagnostic Accuracy Studies (version 2) tool.

RESULTS

In total, 98 observational or retrospective studies were included. The diagnostic odds ratio of SLNB was 326.165 (95% confidence interval [CI]: 231.477-459.587; I²  = 0%). The area under the summary receiver operating characteristic curve was 0.982. Sensitivity was 0.827 (95% CI: 0.804-0.848), and specificity was 0.981 (95% CI: 0.975-0.986). The correlation between sensitivity and the false positive rate was -0.076, which indicates that heterogeneity did not exist. Subgroup analyses were performed with the subgroups reference test type, publication year, and study type. No significant difference was found within the reference test type subgroup. However, differences within the publication year and study type subgroups were significant, where the retrospective study subgroup was significantly more sensitive and specific than the prospective study subgroup.

CONCLUSION

Results of this meta-analysis imply that the high specificity of SLNB supports its role as a diagnostic tool for patients with clinical tumor stage (CT)1-2 clinically negative (N0) OSCC. More studies should be done to further verify the results of this study.

LEVEL OF EVIDENCE

2a Laryngoscope, 131:E459-E465, 2021.

Individualized Prophylactic Neck Irradiation in Patients with cN0 Head and Neck Cancer Based on Sentinel Lymph Node(s) Identification: Definitive Results of a Prospective Phase 1-2 Study

PURPOSE

This prospective, nonrandomized, interventional phase 1-2 study investigated the individualization of elective node irradiation in clinically N0 head and neck squamous cell carcinoma by sentinel lymph node (SLN) mapping with single-photon emission computed tomography/computed tomography (SPECT/CT) and its impact on tumor control and radiation-related toxicity.

METHODS AND MATERIALS

Forty-four patients with clinically N0 head and neck squamous cell carcinoma treated with definitive (chemo-)radiation therapy were imaged with SPECT/CT after ^99mTc nanocolloid injection around the tumor. The neck levels containing up to the 4 hottest SLNs were selected for prophylactic irradiation. A comparative virtual planning was performed with the selection of neck levels based on the current international guidelines. Regional control was monitored as a function of the selected volume. Dosimetric data for the organs at risk were compared between the plans. Normal tissue complication probability (NTCP) rates were derived for xerostomia, dysphagia, and hypothyroidism to predict the clinical benefit and correlated to quality-of-life (QoL) assessments at 6 months.

RESULTS

Sixteen percent of patients presented unpredicted lymphatic drainage, and 48% drained unilaterally. The nodal clinical target volume based on lymphoscintigraphy was smaller than the nodal clinical target volume based on international guidelines by a factor of 2 (P < .0001). After a median follow-up of 46 months, only 1 patient experienced a regional relapse in a nonirradiated area. Significant median dose reductions to organs at risk were observed, particularly to contralateral salivary glands in patients with unilateral drainage (14.6-28.1 Gy) and to the thyroid gland in all patients (22.4-48.9 Gy). Median NTCP reductions were observed for xerostomia (0.3% to 13.7%), dysphagia (1.7% to 10.8%), and hypothyroidism (14.0% to 36.1%). QoL at 6 months was improved, particularly in patients irradiated unilaterally.

CONCLUSIONS

Neck SLN mapping with SPECT/CT individualizes and reduces the elective nodal target volumes without compromising the regional control. The NTCP rates were reduced and favorable QoL were observed in all patients, particularly in the case of unilateral irradiation.

Sensitivity and specificity of sentinel lymph node biopsy in patients with oral squamous cell carcinomas using indocyanine green fluorescence imaging

PURPOSE

The purpose of this clinical study was to evaluate the sensitivity and specificity of cervical sentinel lymph node biopsy after mapping with indocyanine green fluorescence (ICG) for imaging early-stage oral cancer.

PATIENTS AND METHODS

A sentinel lymph node biopsy (SLNB) was performed during a selective neck dissection (SND) in 20 patients with oral squamous cell carcinoma (OSCC, cT1 or cT2, N0 status). The sentinel lymph nodes (SLN) were identified using an infrared video camera after ICG injection. Lymph nodes were examined histologically. The endpoint of this study was to investigate the rate of false-negative results in SLNB.

RESULTS

Sentinel lymph nodes could be detected after 8.1 min (range 1-22 min). In eight out of 20 cases, lymph node metastases were found during histopathological evaluation of the neck dissection specimen. In four cases a metastasis could be found in the detected SLN (sensitivity 50%). In the other four cases metastases were found in different lymph nodes. Specificity was 100%, positive predictive value 100%, and negative predictive value 75%.

CONCLUSION

In this study, reliability of sentinel lymph node biopsy after ICG imaging could not be verified, as there were false-negative results in 50% of the cases. Therefore, SND can still be recommended as for patients with cT1 or cT2 OSCC, and a N0 neck status.

Sentinel lymph node biopsy for oral squamous cell carcinoma. Where are we now?

Recent data have confirmed that elective surgical management of the cN0 neck improves survival in patients with early (T1-T2) oral squamous cell carcinoma (SCC), and is better than watchful waiting. However, elective neck dissection (END) may not always be necessary. Sentinel node biopsy (SNB), which is a reliable staging test for patients with early disease and a radiologically N0 neck, can detect occult metastases with a sensitivity of 86%-94%. Patients with no sign of metastases on SNB could avoid neck dissection, and individual treatment should reduce both morbidity and cost. Currently, SNB for oral SCC is available at a limited number of centres in the UK, but this is likely to change as national guidelines have recommended that it is incorporated into the standard treatment pathway. It is therefore important to understand the current evidence that supports its use, its limitations and related controversies, and to plan for a validated training programme.

Diagnostic Efficacy of Sentinel Lymph Node Biopsy in Early Oral Squamous Cell Carcinoma: A Meta-Analysis of 66 Studies

OBJECTIVES

The diagnostic efficacy of sentinel lymph node biopsy(SLNB) in early oral squamous cell carcinoma(OSCC) still remains controversial. This meta-analysis was conducted to assess the diagnostic value of SLNB in clinically neck-negative T1-2 OSCC.

METHODS

A systematic literature search for relevant literature published up to September 11, 2016 was conducted in PubMed, Embase, Web of Science, Cochrane Library and ClinicalTrials, and the reference lists of eligible studies were examined. Data from different studies were pooled to estimate the summary sentinel lymph node(SLN) identification rate, sensitivity, negative predictive value. Summary receiver operator characteristic curve(SROC) was plotted and area under the SROC curve (AUC) was calculated to evaluate the overall diagnostic efficacy. Threshold effect was assessed with use of the spearman correlation coefficient. Between-study heterogeneity was tested using the Q tests and the I2 statistics. Subgroup analyses were conducted in view of the greater effect of different study characteristics on diagnostic efficacy of SLN. Deeks' funnel plot asymmetry test was performed to evaluate publication bias. Sensitivity analysis was evaluated through omitting studies one by one and comparing the pooled results of random-effects model and fixed-effects model. All analyses were performed using Review Manager (version 5.3.5), Meta-DiSc (version 1.4), Comprehensive Meta Analysis (version 2.0) and STATA (version 12).

RESULTS

66 studies comprising 3566 patients with cT1-2N0 OSCC were included in this meta-analysis. The pooled SLN identification rate was 96.3%(95% CI: 95.3%-97.0%). The pooled sensitivity was 0.87 (95% CI: 0.85-0.89), pooled negative predictive value was 0.94 (95% CI: 0.93-0.95), and AUC was 0.98 (95% CI: 0.97-0.99). Subgroup analyses indicated that SLN assessment with immunohistochemistry(IHC) achieved a significantly higher sensitivity than without IHC.

CONCLUSIONS

This meta-analysis suggests that SLNB has a high diagnostic accuracy in cT1-2N0 oral squamous cell carcinoma, and is an ideal alternative to elective neck dissection. Furthermore, the use of IHC can significantly improve SLNB diagnostic sensitivity for early OSCC.

Additional non-sentinel lymph node metastases in early oral cancer patients with positive sentinel lymph nodes

To determine risk factors for additional non-sentinel lymph node metastases in neck dissection specimens of patients with early stage oral cancer and a positive sentinel lymph node biopsy (SLNB). A retrospective analysis of 36 previously untreated SLNB positive patients in our institution and investigation of currently available literature of positive SLNB patients in early stage oral cancer was done. Degree of metastatic involvement [classified as isolated tumor cells (ITC), micro- and macrometastasis] of the sentinel lymph node (SLN), the status of other SLNs, and additional non-SLN metastases in neck dissection specimens were analyzed. Of 27 studies, comprising 511 patients with positive SLNs, the pooled prevalence of non-SLN metastasis in patients with positive SLNs was 31 %. Non-SLN metastases were detected (available from 9 studies) in 13, 20, and 40 % of patients with ITC, micro-, and macrometastasis in the SLN, respectively. The probability of non-SLN metastasis seems to be higher in the case of more than one positive SLN (29 vs. 24 %), the absence of negative SLNs (40 vs. 19 %), and a positive SLN ratio of more than 50 % (38 vs. 19 %). Additional non-SLN metastases were found in 31 % of neck dissections following positive SLNB. The presence of multiple positive SLNs, the absence of negative SLNs, and a positive SLN ratio of more than 50 % may be predictive factors for non-SLN metastases. Classification of SLNs into ITC, micro-, and macrometastasis in the future SLNB studies is important to answer the question if treatment of the neck is always needed after positive SLNB.

Sentinel node biopsy for oral cancer: A prospective multicenter Phase II trial

OBJECTIVE

A recent study identified a survival benefit with prophylactic neck dissection (ND) at the time of primary surgery as compared with watchful waiting followed by therapeutic neck dissection for nodal relapse, in patients with cN0 oral squamous cell carcinoma (OSCC). Alternative management of cN0 neck cancer is recommended to minimize the adverse effects of ND, indicating the need for sentinel node biopsy (SNB) and limited neck dissection. We conducted a multicenter Phase II study to examine the feasibility of SNB for clinically N0 OSCC.

METHODS

Previously untreated N0 OSCC patients (n=57) with clinical late-T2 or T3 tumors were enrolled across 10 institutions. SNB navigated with multislice frozen section analysis of sentinel nodes (SNs) and SNB supported sentinel node lymphatic basin dissection (SN basin dissection) were performed in a one-stage procedure. The endpoint was to investigate the rate of false-negative metastases after SN basin dissection and SNB alone.

RESULTS

Most tumors were late-T2 lesions (n=50; 87.7%). SNs were identified in all patients. A total of 196 SNs were detected. Among these SNs, 35 (17.8%) were positive for metastasis (9 in level I, 12 in level II, 12 in level III, 1 in level V and 2 in the contralateral region of the neck). The false-negative rate of SNB supported by SN basin dissection and SNB alone was 4.5% and 9.1%, respectively. The concordance of the SN status in intraoperative frozen sections with the permanent histopathology was 97.4% (191/196). The sensitivity and specificity of intraoperative pathological evaluation were 85.7% (30/35) and 100% (30/30), respectively. The 3-year overall survival (OS) and disease-free survival was 89.5% and 82.5%, respectively. The OS of SN-negative patients was significantly longer than that of SN-positive patients (P=0.047).

CONCLUSION

The current study verified that SN basin dissection was a useful back-up procedure for SNB performed as a one-stage procedure, showing a low false-negative rate. SNB alone is an appropriate staging method for patients with clinical N0 staging, and a reliable procedure to determine the appropriate levels for neck dissection.

Indirect computed tomography lymphography identifies lymph node metastasis in rabbit pyriform sinus VX2 carcinoma

Indirect computed tomography lymphography (CT-LG) could be used to determine the regional spread of cancer and assess lymphatic function by the interstitial delivery of diagnostic agents. Few studies have been reported on its use in pyriform sinus carcinoma. The aim of the present study was to establish the rabbit VX2 tumor as a model for pyriform sinus carcinoma and to observe its neck lymph node metastasis by indirect CT-LG. VX2 tumor tissue suspension was transplanted into the pyriform sinus submucosa of 15 rabbits under direct laryngoscope. Rabbits were randomly placed into one of three groups, each comprised of five rabbits. Observation of the tumor growth and neck lymph node metastases were taken on days 14 (group 1), 21 (group 2) and 28 (group 3) following transplantation using the method of indirect CT-LG. VX2 tumors were transplanted successfully in all rabbits. Deep cervical lymph nodes were enhanced clearly in indirect CT-LG. The contrast agent filling defected appeared on the metastasis nodes while the lymph node without metastasis was smooth. The metastasis rates of deep cervical lymph nodes were 100% in all three groups on CT-LG. The CT attenuation value of CT-LG reached peak values of 400 and 600 Hu at 1 and 3 min after the injection, which then decreased gradually. In this study, CT-LG could demonstrate the internal architecture of lymph nodes and their lymphatic vessels, and therefore may have the advantages of radiological methods such as B ultrasound, CT, magnetic resonance imaging and positron emission tomography.

Does HMGB1 predict occult neck lymph node metastasis in early tongue carcinoma? A case-control study of 26 patients

OBJECTIVE

This study examined whether the occurrence of late neck metastasis in early tongue squamous cell carcinoma can be predicted by evaluating HMGB1 (high mobility group box 1) expression in the primary lesion.

METHODS

A case-control study was conducted. The cases comprised 10 patients with late neck metastasis. The controls consisted of 16 patients without recurrence. All were examined immunohistochemically for HMGB1 protein expression. The odds ratio for late neck metastasis in relation to HMGB1 was estimated.

RESULTS

RESULTS for HMGB1 were dichotomised into positive staining scores (score, 5-7) and negative scores (0-4). Six cases (60 per cent) and four controls (25 per cent) were HMGB1-positive. Although no significant result was seen, compared with HMGB1-negative patients the odds ratio for late neck metastasis in HMGB1-positive patients was 3.8 (95 per cent confidence interval, 0.6-26.5) after adjusting for other factors.

CONCLUSION

In the present study, immunohistochemical study of HMGB1 in early tongue squamous cell carcinoma did not appear to be very useful for predicting occult neck metastasis. Further study is necessary to clarify the relationship between HMGB1 expression and late neck metastasis in early tongue squamous cell carcinoma.

Usefulness of sentinel node navigation surgery in the management of early tongue cancer

OBJECTIVE

To determine the validity of sentinel node navigation surgery (SNNS) in early stage tongue cancer, the occurrence rate of postoperative cervical metastasis (POCM) after lead plate technique (LPT) introduction and survival rates in patients who underwent SNNS were analyzed.

METHODS

SNNS was performed in 29 patients (stage I: 14, stage II: 15) from 2000 to 2007. Tc-labeled phytate was prepared as a radiotracer a day before SNNS. The sentinel node (SN) was then examined pathologically during surgery. For cases where metastasis in SN was positive, neck dissection was performed. Occurrence of POCM after LPT introduction was compared with that before LPT introduction. 'Wait and see' policy was performed in 52 patients (stage I: 27, stage II: 25) from 1987 to 1999 as a historical control. The observation period of SNNS cases and 'wait and see' policy cases ranged from 10 months to 165 months (median: 91 months) and from 7 months to 268 months (median: 87 months), respectively.

RESULTS

Six of the 29 SNNS cases (21%) were proven metastatic SNs. Before LPT introduction, POCM occurred in 2 of the 15 cases, while we had no occurrences after LPT introduction. The 5-year overall survival rate of the 29 patients who underwent SNNS and the 52 patients with 'wait and see' policy were 96% and 84%, respectively, and there was statistical significance in the two groups (p<0.05).

CONCLUSIONS

As the survival rate of the patients with the SNNS tended to be better than that with the 'wait and see' policy in our cases, SNNS could avoid unnecessary neck dissection. SNNS provides useful information regarding decision-making for neck dissection in early stage tongue cancer.

SPECT/CT lymphoscintigraphy of sentinel node(s) for superselective prophylactic irradiation of the neck in cN0 head and neck cancer patients: a prospective phase I feasibility study

Background

Clinically node negative HNSCC patients have a risk ranging between 18 and 45% of occult metastases, making prophylactic irradiation mandatory. Selective irradiation of nodal target volume based on international guidelines is practice. Anyway, about half the tumours lying in an anatomical subsite known to potentially drain bilaterally effectively do so, leading to unnecessary large volume irradiation. Moreover, 15% of the tumours show drainage outside of predicted basin, increasing the risk for potential geographical misses. Three-dimensional SPECT/CT lymphoscintigraphy (LS) of sentinel node(s) may help to individualize nodal target volume selection. This prospective phase I study explores its feasibility and the dosimetric impact.

Methods

Ten cN0 HNSCC patients eligible for definitive radiotherapy were imaged with SPECT/CT after ^99mTc nanocolloid injection around the tumour. The neck levels containing up to four hottest nodes were identified and selected for prophylactic irradiation (CTVn-LS) by volumetric modulated arc therapy. A comparative virtual planning was performed with volumes selected according to international guidelines (CTVn-IG).

Results

Migration was observed in all patients (one with gamma probe only). 2.9 sentinel nodes were detected per patient on average. In some patients, accurate localization was difficult when not using thermoplastic mask for SPECT/CT. CTVn-LS was totally encompassed by CTVn-IG in all patients but one (unpredicted drainage in retropharyngeal level). On average, CTVn-LS and related planning target volumes were two times smaller than IG ones. This led to significant dose decrease in identified organs at risk as well as remaining volume at risk.

Conclusions

SPECT/CT LS is a promising tool to individualize prophylactic node CTV in cN0 HNSCC patients eligible for definitive radiotherapy. Oncological safety must be confirmed by ongoing phase II study.

Novel Indocyanine Green-Phytate Colloid Technique for Sentinel Node Detection in Head and Neck: Mouse Study

OBJECTIVE

Sentinel node navigation surgery using real-time, near-infrared imaging with indocyanine green is becoming popular by allowing head and neck surgeons to avoid unnecessary neck dissection. The major drawback of this method is its quick migration through the lymphatics, limiting the diagnostic time window and undesirable detection of downstream nodes. We resolved this problem by mixing indocyanine green (ICG) with phytate colloid to retard its migration and demonstrated its feasibility in a nude mouse study.

STUDY DESIGN

Experimental prospective animal study.

SETTINGS

Animal laboratory.

SUBJECTS AND METHODS

Indocyanine green at 3 concentrations was tested to determine the optimal concentration for sentinel lymph node detection in a mouse model. Effect of indocyanine green with phytate colloid mixture solutions was also analyzed. Indocyanine green or mixture solution at different mixing ratios were injected into the tongue of nude mice and near-infrared fluorescence images were captured sequentially for up to 48 hours. The brightness of fluorescence in the sentinel lymph node and lymph nodes further downstream were assessed.

RESULTS

Indocyanine green concentration >50 μg/mL did not improve sentinel lymph node detection. The addition of phytate colloid to indocyanine green extended the period when sentinel lymph node was detectable. Second echelon lymph nodes were not imaged in mice injected with the mixture, while these were visualized in mice injected with indocyanine green alone.

CONCLUSION

This novel technique of ICG-phytate colloid mixture allows prolonged diagnostic time window, prevention of downstream subsequent nodes detection, and improved accuracy for the detection of true sentinel lymph nodes.

Diagnostic value of sentinel lymph node biopsy in head and neck cancer: a meta-analysis

This study aimed to evaluate the diagnostic reliability of sentinel lymph node biopsy in patients with squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, and larynx by reviewing the published literature. A systematic literature review was performed using MEDLINE from 1970 to 2011. With Boolean search strings, search terms included sentinel node, supraglottic, supraglottis, tongue, head and neck, oral, pharynx, laryngeal, and larynx. Additional studies were identified through article references. Duplicate data and articles were excluded based on treating institution and study inclusion time period. Additional studies were excluded if the head and neck subsite or tumor stage was not specifically identified or if the sentinel lymph node biopsy occurred in previously treated necks. All patients had sentinel lymph node biopsy performed followed by a concurrent neck dissection. Twenty-six studies met our inclusion criteria (n = 766 patients). The pooled sensitivity and negative predictive value of SLNB for all head and neck tumors was 95 % (95 % CI 91-99 %) and 96 % (95 %CI 94-99 %), respectively. The overall sensitivity and negative predictive value of SLNB in the subset of oral cavity tumors (n = 631) was 94 % (95 % CI 89-98 %) and 96 % (95 % CI 93-99 %), respectively. One-hundred percent of oropharyngeal (n = 72), hypopharyngeal (n = 5), and laryngeal (n = 58) tumor sentinel lymph biopsy results correlated with subsequent neck dissections giving a negative predictive value of 100 %, showing that, sentinel lymph node biopsy is a valid diagnostic technique to correctly stage regional metastases in patients with head and neck squamous cell carcinoma.

Platinum concentration in sentinel lymph nodes after preoperative intra-arterial cisplatin chemotherapy targeting primary tongue cancer

CONCLUSION

We conclude that intra-arterially injected cisplatin passed via lymph flow into sentinel nodes (SNs) as the platinum concentration in the SNs was higher than that in the non-sentinel nodes (NSNs). It is possible that preoperative intra-arterial chemotherapy targeting primary cancer also has a therapeutic effect on subclinical metastatic SNs.

OBJECTIVES

Intra-arterial chemoradiotherapy has been reported to be effective against not only primary tumors but also nodal metastases. We considered the hypothesis that intra-arterially injected cisplatin passed via lymph flow into regional nodes. This study aimed to investigate intra-arterially injected cisplatin distribution to regional nodes by comparing platinum concentrations in SNs and NSNs.

METHODS

Five patients with T1-2 N0 tongue cancer were treated with preoperative intra-arterial chemotherapy (cisplatin, 100 mg/m(2)) targeting primary cancer. Partial glossectomy together with SN biopsy and elective neck dissection were performed 2 weeks after intra-arterial chemotherapy. Platinum concentrations in the lymph nodes were measured using a Zeeman atomic absorption spectrometer.

RESULTS

Thirteen SNs were harvested together with eight NSNs from the areas adjacent to the SNs. Platinum concentrations were then measured, revealing a significant difference in platinum concentration between the SNs and the NSNs (mean ± SD, 0.682 ± 0.246 µg/g vs 0.506 ± 0.274 µg/g; p = 0.049).

Intraoperative molecular assessment for lymph node metastasis in head and neck squamous cell carcinoma using one-step nucleic acid amplification (OSNA) assay

BACKGROUND

Conventional intraoperative pathological examination for Sentinel node navigation surgery (SNNS) has been controversial. We evaluated the efficacy of one-step nucleic acid amplification (OSNA) assay for intraoperative diagnosis of cervical lymph node (CLN) metastasis compared with histopathological examination in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

A total of 175 CLNs dissected from 56 patients with HNSCC who underwent surgery at Aichi Cancer Center, Kyorin University, Gunma University or Fukushima Medical University, between April 2008 and December 2011 were enrolled. CLN samples were sectioned into four equal pieces, with two of each used for OSNA assay and other histopathological examinations. The diagnostic value of OSNA assay in HNSCC patients in predicting the results of histopathological diagnosis was evaluated using the area under the receiver operating characteristic (AUROC) curve.

RESULTS

OSNA assay showed acceptable efficacy in the detection of pathological CLN metastasis (AUROC 0.918, 95 % confidence interval [CI] 0.852-0.984). Regarding the CK19mRNA cutoff value, the optimum cutoff point in HNSCC patients was 131 copies/μl (sensitivity: 82.4, 95 % CI 65.5-93.2; specificity: 99.3, 95 % CI 96.1-100.0; positive likelihood ratio 116.1; negative likelihood ratio 0.2].

CONCLUSIONS

We demonstrated that OSNA assay is useful in intraoperative diagnosis for CLN metastasis in patients with HNSCC. OSNA assay could be applied for SNNS in HNSCC patients.